Transmembrane receptor tyrosine kinases (RTKs) comprise an evolutionarily conserved family of structurally related proteins. The gene Mer is a member of the Tyro3/Axl/Mer (TAM) receptor kinase family and a proto-oncogene. Its abnormal expression and activation is found in conjunction with human cancers such as pituitary adenomas, mantle cell lymphomas, and T-cell acute lymphoblastic leukemia.
The ATP-binding site is similar for all protein kinases. For this reason, it is challenging to find an inhibitor that is specific for the Mer. Compound-52, a 2,6,9-trisubstituted purine that occupies the ATP-binding site, was actually the first molecule that was found to be successful in inhibiting Mer (J Struct Biol. 2009 February; 165(2): 88-96). This inhibitor has, however, limited potency and lack of selectivity. Lately, several compounds have been unveiled mostly by modifying Compound-52 including UNC-569, UNC-1062, and UNC-2025 (ACS Med Chem Lett. 2012 Feb. 9; 3(2):129-134, Eur J Med Chem. 2013 July; 65:83-93, J Med Chem. 2014 Aug. 28; 57(16):7031-41).
It is an object of the invention to provide reagents and methods of regulating a receptor tyrosine kinase Mer. This and other objects of the invention are provided by one or more of the embodiments described below.